When they sign up, they must agree to donate at least 2% of their exit proceeds to a charitable cause.

At the time they get acquired, be it through an acquisition or an IPO, they transfer the money they agreed to Founders Pledge, which distributes the money to charitable causes chosen by the pledger.

Rocket Internet founder Oliver Samwer. Getty Images/Hannelore Foerster Founders Pledge CEO David Goldberg said at a launch event in Berlin last week that it can be hard for founders to know how to part with their money when they end up with seven figures or more in their bank account. He added that Founders Pledge takes the stress out of philanthropy for them.

In total, some 600 people have signed up to the philanthropic initiative and $227 million (£181 million) have been pledged to charity, according to Goldberg. That includes high-profile people like Mustafa Suleyman, cofounder of Alphabet-owned artificial intelligence lab DeepMind, and Sam Altman, president of Silicon Valley tech incubator Y Combinator, he added.

"The German community of pledgers has already committed a total $12 million (£9 million) to charity, and with ambassadors such as Andreas Haug (e.ventures), Sebastian Pollock (Amorelie), and Jeannette zu Fürstenberg (La Famiglia), we are aiming to triple our German pledge value within the year," Goldberg told Business Insider in an email.